OBJECTIVETo explore the histological change in suture of zygomatic bone for the zygomatic suture direct distraction osteogenesis.

METHODSThe zygomatic bone was distracted by 3-D external distraction appliance without osteotomy. The specimens were taken 1, 3, 5 and 8 weeks after, and then examined histologically and compared with the blank contralateral side.

RESULTSThere were lots of fibroblasts, osteoblasts and capillary vessels in the distracted suture tissues one week after distraction, and the fibers were observed to connect the sides of suture and arranged orderly. The surfaces of the expanded suture were irregular. Bone formation was active in the expanded side. The bone trabeculae were mature and oriented in the direction of distraction in the distracted sides at 3 weeks. A great amount of new woven bones were found in 5-week specimen. New bones were formed completely 8 weeks after the distraction.

CONCLUSIONSNew bone formed rapidly in the distracted side of zygomatic bone under suture distraction osteogenesis without osteotomy.